The Bio-Behavioral Core will advance high-impact, integrated biomedical, behavioral, and social science research in HIV prevention and care from conceptualization to proposal submission and from data collection to interpretation and dissemination. Although effective combination antiretroviral therapy (ART) can reduce HIV transmission, new infections continue to occur, and diagnoses surpass deaths each year. Every biomedical strategy for preventing and treating HIV infection (e.g., ART, PrEP, PEP, intravaginal rings, condoms, microbicides, and future vaccines and broadly neutralizing monoclonal antibodies] has behavioral components that influence efficacy and effectiveness. Unless biomedical strategies are acceptable, widely disseminated, and adhered to and take into consideration co-morbidities such as mental health and substance use and health and social disparities, their impact on the AIDS epidemic will be limited. The Bio-Behavioral Core will provide a comprehensive approach that integrates biomedical, behavioral and social science, and clinical perspectives for HIV prevention and treatment research, using Syndemics Theory as a guiding framework for advancing bio- behavioral research. The Core has three Specific Aims: (1) to stimulate high-impact bio-behavioral research on emerging priority topics at the interface of biomedical and behavioral science; (2) to provide expertise on selection of biological measures, sample collection and assay, and interpretation of resulting data; and (3) to prioritize clinical perspectives through partnerships with HIV and non-HIV care providers. The Bio-Behavioral Core will accomplish its Aims through a range of functions that include expert consultation to HIV Center researchers on research design, intervention development, biomarkers, social science theories, and research partnerships with providers; Scientific Working Groups, integrated diverse teams of biomedical, clinical, and social science researchers who come together to develop competitive research proposals that meet the most pressing clinical, scientific, and policy challenges; and annual Symposia that bring preeminent researchers to the HIV Center for intensive exploration of selected pressing scientific dilemmas to stimulate new scientific questions and, ultimately, multidisciplinary research grant proposals. We will identify shared scientific goals that bridge disciplinary silos; build collaborative interdisciplinary teams to address these goals; and support an integrated bio-behavioral research agenda. The Core Director will be Laurie Bauman, Ph.D., a sociologist, Professor of Pediatrics, and Director of the Prevention Intervention Research Center at the Albert Einstein College of Medicine. Core Co-Director, Michael Yin, M.D., is an Associate Professor of Medicine at Columbia University who manages care for PLWH, provides PrEP-related services, and is an investigator in the CUMC AIDS Clinical Trials Group (ACTG). Through the strengths of its Members and Affiliates in behavioral, social, and biomedical sciences and clinical research and care, the Bio- Behavioral Core will provide essential infrastructure to support a Center-wide learning community.